1. Field
The present disclosure generally relates to manufacturing and, in particular, to performing functions on a workpiece using robots. Still more particularly, the present disclosure relates to a method and apparatus for a robot self-locating on a movement surface to perform functions on a workpiece.
2. Background
In manufacturing, robots may perform functions on a workpiece. Some robots may be articulated arm robots tethered to the manufacturing floor. Some other robots may travel along a surface using a movement system. When a robot travels using a movement system, the robot may keep track of its location. Functions may be desirably performed within engineering tolerances on desired locations on a workpiece. Knowledge of a robot's location may be important for controlling a location of function on a workpiece.
When a robot travels over the workpiece, the location of the robot may be determined by markings placed on the workpiece. For example, the robot may sense a guidance path on the workpiece. Further, the robot may perform functions based on target indicators. Target indicators may indicate locations where the robot may desirably perform a function.
Some robots may travel along a movement surface separate from the workpiece. The movement surface may be moved relative to the workpiece. As a result, a movement surface may not have a guidance path or target indicators.
A location of the robot traveling along a movement surface may be initially determined using any desirable method. The robot may then estimate future locations through odometry. Odometry may include motion sensors to estimate the change of the robot's location over time. However, odometry may introduce inaccuracies into the estimated location. Inaccuracies due to odometry may compound over time. The inaccuracies may cause the functions to be performed on the workpiece outside the tolerance of the desired locations. Therefore, it would be desirable to have a method and apparatus that take into account at least some of the issues discussed above, as well as other possible issues.